Help me fix these poor ML Sequels - Page 2 - diyAudio
Go Back   Home > Forums > Loudspeakers > Planars & Exotics

Planars & Exotics ESL's, planars, and alternative technologies

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 12th January 2014, 09:18 PM   #11
X83 is offline X83  United States
diyAudio Member
 
Join Date: Sep 2013
You may want to just bypass all those inductors & capacitors and use an active crossover.
  Reply With Quote
Old 12th January 2014, 10:06 PM   #12
diyAudio Member
 
Join Date: Jun 2011
Quote:
Originally Posted by X83 View Post
You may want to just bypass all those inductors & capacitors and use an active crossover.
No, I'd rather sort what I have and possibly tweak it once everything is working properly.

So how about that schematic?

Thanks

Eric
  Reply With Quote
Old 12th January 2014, 10:26 PM   #13
diyAudio Member
 
Join Date: Feb 2008
Location: Jackson,michigan
The caps could be just fine.
The inductor's are toast and there is a reason for this.

Either they were abused and/or the bias supply quit working and then abused because there was no sound.
And/or, the step-up transformer is shorted due to the abuse causing it to fry the inductors from the overcurrent.

I would start with square one, and that is to determine if the Bias supply is working or build a new one.
Check the step up transformer if it is working properly and get some sound out of the panels first before you waste your money on new crossover components.

The one main reasons is, If you decide to use a different step-up transformer then your new crossover components won't be of the proper values for the transformer should you change it, unless it is an exact OEM part.

Must know the transformers primary inductance before you can start to design a crossover for them.

It is much cheaper and easier to go active as X83 suggested and will cost about the same if not less by the time it is all said and done!!
And, You may very well have a better sound in the long run as well.

FWIW

jer
  Reply With Quote
Old 13th January 2014, 12:21 AM   #14
diyAudio Member
 
Join Date: Jun 2011
Actually it appears all the original resistors burned up. Other than one missing inductor they all look original and in good shape.

How do I determine if my bias supply is functional and what resistances should I be looking for in order to determine the transformers are ok?

Thanks

Eric
  Reply With Quote
Old 13th January 2014, 03:43 AM   #15
diyAudio Member
 
Join Date: Jun 2011
Below is a photo of my bias supply. If I plug it in I should get how many volts from the terminals in the blue output block on the upper right?


Thanks

Eric

Click the image to open in full size.
  Reply With Quote
Old 13th January 2014, 04:05 AM   #16
diyAudio Member
 
Join Date: Feb 2008
Location: Jackson,michigan
From what I have read about the ML's there should be about 3Kv to 4Kv coming out of it.
You won't be able to measure it with a common DMM unless you make a HV divider circuit as I have described in earlier threads.

Here are the plans as to what I am referring to and hope they give you some idea of how to go about measuring such voltages accurately and safely.

Here are the links,

http://hyperphysics.phy-astr.gsu.edu...ic/voldiv.html

how can test the stator insulation and mylar coating?

http://www.esldiy.com/index.php?topic=5.msg24#msg24

http://www.esldiy.com/index.php?topic=177.msg311#msg311

ESL Power supply question?

jer
Attached Images
File Type: jpg TRANSFORMER TESTER1.jpg (303.6 KB, 114 views)
File Type: jpg Updated Test Jig Schematic.jpg (68.5 KB, 107 views)
File Type: jpg FINNISHED BIAS SUPPLY Page1.jpg (269.7 KB, 105 views)
File Type: jpg FINNISHED BIAS SUPPLY Page2.jpg (220.3 KB, 103 views)

Last edited by geraldfryjr; 13th January 2014 at 04:20 AM.
  Reply With Quote
Old 16th January 2014, 02:16 AM   #17
diyAudio Member
 
Join Date: Jun 2011
Let me re ask a question. The burned resistors in the crossovers were a result of being over driven by the amplifier NOT a failed power supply correct?

Can an over driven crossover cause the power supply to fail?

Thanks

Eric
  Reply With Quote
Old 16th January 2014, 02:28 AM   #18
diyAudio Member
 
Join Date: Feb 2008
Location: Jackson,michigan
Yes, most likey.


Second Question~
No, The driving Audio signal and cross over components have very little to no effect on the bias voltage.
I have seen the bias voltage get slightly modulate when the audio signal is stepped up but this has nothing to do with the Bias supply's ability to produce the required voltages under normal circumstances.

If there was ever a chance that the driven audio was high enough to overcome the breakdown voltage of the stack of diodes in the bias supply then I doubt the step-up transformers would even last long enough for that to happen and would most likely burn up First.

jer
  Reply With Quote
Old 16th January 2014, 03:20 AM   #19
diyAudio Member
 
Join Date: Jun 2011
Ok. This is what I'm thinking. Since I have most of the components to rebuild the crossovers I'm going to do just that and see what I get.

I am missing one of the larger inductors though so I will need to find a replacement. Can someone tell me the values of the two large inductors so I can check to see which ones I have and find the one I need?

Finally if I don't get sufficient volume after I wash the panels I will recoat them.

Either talk me down or wish me luck.

Eric
  Reply With Quote
Old 16th January 2014, 05:13 AM   #20
diyAudio Member
 
Join Date: Feb 2008
Location: Jackson,michigan
I so wish you much luck in getting those things to work.

It sad that you have to go to such a measure, But I hope that you do get them running again!!!

If there is anything else you need to know just ask !!

Good Luck !!!

jer
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Is this a poor result? jamikl Multi-Way 2 18th August 2010 02:56 AM
Perpetuum-Ebner PE66: To fix or not to fix... Grendel the Cat Everything Else 0 6th April 2007 05:37 AM
ML-TL or ML-TQWT with very low Qt driver Henkjan Full Range 6 29th September 2006 02:29 PM
What is the Q of a (ML)-TQWT, (ML)-TML, etc Elam Full Range 0 18th June 2005 08:56 AM
Small box for FE103 - ML TL or ML TQWT? ChuckT Full Range 15 28th July 2004 05:56 AM


New To Site? Need Help?

All times are GMT. The time now is 08:14 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2